forked from Minki/linux
328985b2c6
In readiness for 64k pages, when THREAD_SIZE will be less than PAGE_SIZE, ppc64 uses kmalloc() rather than __get_free_pages() to allocate kernel stacks, and since thread_info.h was merged, so does ppc32. However that adds some overhead which we don't really want when PAGE_SIZE <= THREAD_SIZE (including all ppc32 machines), so this patch avoids it. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
143 lines
4.1 KiB
C
143 lines
4.1 KiB
C
/* thread_info.h: PowerPC low-level thread information
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* adapted from the i386 version by Paul Mackerras
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_POWERPC_THREAD_INFO_H
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#define _ASM_POWERPC_THREAD_INFO_H
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#ifdef __KERNEL__
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/* We have 8k stacks on ppc32 and 16k on ppc64 */
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#ifdef CONFIG_PPC64
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#define THREAD_SHIFT 14
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#else
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#define THREAD_SHIFT 13
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#endif
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#define THREAD_SIZE (1 << THREAD_SHIFT)
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#ifndef __ASSEMBLY__
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#include <linux/config.h>
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#include <linux/cache.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <linux/stringify.h>
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/*
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* low level task data.
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*/
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struct thread_info {
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struct task_struct *task; /* main task structure */
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struct exec_domain *exec_domain; /* execution domain */
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int cpu; /* cpu we're on */
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int preempt_count; /* 0 => preemptable,
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<0 => BUG */
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struct restart_block restart_block;
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/* set by force_successful_syscall_return */
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unsigned char syscall_noerror;
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/* low level flags - has atomic operations done on it */
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unsigned long flags ____cacheline_aligned_in_smp;
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};
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/*
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* macros/functions for gaining access to the thread information structure
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*
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* preempt_count needs to be 1 initially, until the scheduler is functional.
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*/
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.cpu = 0, \
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.preempt_count = 1, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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.flags = 0, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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/* thread information allocation */
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#ifdef CONFIG_DEBUG_STACK_USAGE
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#define THREAD_INFO_GFP GFP_KERNEL | __GFP_ZERO
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#else
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#define THREAD_INFO_GFP GFP_KERNEL
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#endif
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#if THREAD_SHIFT >= PAGE_SHIFT
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#define THREAD_ORDER (THREAD_SHIFT - PAGE_SHIFT)
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#define alloc_thread_info(tsk) \
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((struct thread_info *)__get_free_pages(THREAD_INFO_GFP, THREAD_ORDER))
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#define free_thread_info(ti) free_pages((unsigned long)ti, THREAD_ORDER)
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#else /* THREAD_SHIFT < PAGE_SHIFT */
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#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, THREAD_INFO_GFP)
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#define free_thread_info(ti) kfree(ti)
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#endif /* THREAD_SHIFT < PAGE_SHIFT */
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#define get_thread_info(ti) get_task_struct((ti)->task)
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#define put_thread_info(ti) put_task_struct((ti)->task)
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/* how to get the thread information struct from C */
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static inline struct thread_info *current_thread_info(void)
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{
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register unsigned long sp asm("r1");
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/* gcc4, at least, is smart enough to turn this into a single
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* rlwinm for ppc32 and clrrdi for ppc64 */
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return (struct thread_info *)(sp & ~(THREAD_SIZE-1));
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}
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#endif /* __ASSEMBLY__ */
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#define PREEMPT_ACTIVE 0x10000000
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/*
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* thread information flag bit numbers
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
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#define TIF_SIGPENDING 2 /* signal pending */
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#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
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#define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling
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TIF_NEED_RESCHED */
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#define TIF_32BIT 5 /* 32 bit binary */
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/* #define SPARE 6 */
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#define TIF_ABI_PENDING 7 /* 32/64 bit switch needed */
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#define TIF_SYSCALL_AUDIT 8 /* syscall auditing active */
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#define TIF_SINGLESTEP 9 /* singlestepping active */
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#define TIF_MEMDIE 10
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#define TIF_SECCOMP 11 /* secure computing */
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/* as above, but as bit values */
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#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
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#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
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#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
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#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
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#define _TIF_32BIT (1<<TIF_32BIT)
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/* #define _SPARE (1<<SPARE) */
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#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
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#define _TIF_SECCOMP (1<<TIF_SECCOMP)
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#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
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#define _TIF_USER_WORK_MASK (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
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_TIF_NEED_RESCHED)
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_THREAD_INFO_H */
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